1. Field of the Invention
The invention relates to the field of control systems, especially those used in audio and video production and broadcast facilities.
2. Description of the Prior Art
In the past, the audio or video production or broadcast systems included a manually controlled mixing and switching board. These boards were complex and hard to use, requiring skilled operators. The boards were complex because of the large number of available inputs or sources, the multiple outputs available and the options available for each source. The complexity of the system caused errors to be made frequently. Therefore it was desirable to reduce the complexity of the system and the skill level required of the operator to ease programming and reduce the number of mistakes.
One approach to this problem was to fully automate the station by having a computer replace all the operators and oversee the entire operation of the station. A scheduled log of events was entered into the computer and the required tapes were manually loaded in the proper tape units. The computer was programmed to activate the right series of devices at the right time. Problems arose with this type of system because the operators failed to correctly load the taped source material, mechanical malfunctions occurred or there was a need to rapidly rearrange the schedule of events. The computer had limited options in these situations and often could not respond correctly.
Additionally, the static nature of a fully automated system was not acceptable because it was often desired to have a more flexible program environment, one that could be changed by an operator to fit the situation as it arose, be it requests for songs, programs running long or emergency bulletins. This flexibility was readily obtainable in a standard system, but the skilled operator requirements reappeared. Therefore it was desirable to have a system that was flexible but did not require highly trained operators or produce the frequent errors which occurred in manual control boards.
To accommodate advertising and management functions, a broadcast control system also had to provide an accurate log of the actual programs that were played over the air or used in the editing process. Manual systems were inadequate because they required the operator to make a manual log entry for each event which sometimes took more time than was available. Furthermore, manually kept logs were inaccurate since the operator frequently forgot or was unable to make log entries, especially in situations where programming changes and activities were at a peak. Therefore, a control system which automatically logged programs as they were broadcast was highly desirable.